This invention relates to a plug. More particularly it concerns a plug for closing of a pipe bore where the plug comprises an external sleeve made from a flexible material, and a setting mechanism, and where the setting mechanism comprises wedges which between their passive position and their active position run along a curved path.
Pipe bores in this context also comprise unlined boreholes in the ground.
During e.g. exploitation of petroleum, plugs that can be set for closing of a pipe bore are often used. Known plugs typically comprise one or more relatively thick cylindrical bodies made of an elastic material. When the plug is to be set, the bodies are squeezed axially such that they expand radially outwards against the pipe wall.
Plugs according to prior art exhibit some weaknesses. During setting, the position of the plug is unstable by the very fact that the plug end portions are displaced toward each other during the setting. Further, the relatively large mass of elastic material causes that so-called extrusion may occur. During extrusion, some of the flexible material is, due to differential pressure across the plug, squeezed out between the pipe bore and one end portion of the plug, whereby leaks can occur.
When prior art plugs are to be removed, they normally have to be drilled out.